Field of the Invention
The present invention relates to a device for measuring the spin speed of a spinning body when spinning the spinning body using a belt and a pinion gear.
Description of Related Art
Conventionally, to measure the spin speed of a toy that is played by spinning, such as a spinning toy, a mark provided on a side of a driving drum that gives a drive to a spinning toy in a spinning manner or on a side of a spinning toy itself is read by a photo sensor to calculate the number of spin per unit time with a processing device including a timing unit. This type of device for measuring a spin speed is typically known as an encoder which adapts a technique described in JP 2007-24793 A.
However, use of a spin speed measuring device using a photo sensor and a processing device disadvantageously raises the production cost of a toy and likely to cause malfunction when assembled in a toy which is handled in a rough manner.
Meanwhile, a spinning toy device has become popular which is configured to spin a spinning toy mounted on a launcher having a driving drum by spinning the driving drum with a belt called a “winder” to let the spinning toy collide against another spinning toy within an area to compete with each other. The toy has a pinion gear coaxially connected to the driving drum and is configured to spin the driving drum by manually pulling the belt meshing with the pinion gear by a rack provided on a face of the belt.
A feature of this mechanism is that the teeth pitch of the pinion gear and the teeth pitch of the rack are the same throughout their entire lengths.
The object of the present invention is to provide without using a photo sensor a spin speed measuring device for a spinning body at low cost and with very small possibility of malfunction.